NEW YORK (CNNMoney.com) -- In a video posted to his official General Motors blog Thursday, GM vice chairman Bob Lutz took pains to point out that fuel-efficient diesel engines, popular in Europe, will not provide an easy an easy answer to America's petroleum dependence. "Do not assume that the diesel engine is a panacea and is going to make everyone get to a fleet of 36 miles per gallon," Lutz says in the video.
The popular notion Lutz is trying to refute is that diesels, already popular in Europe, offer the fuel economy benefits of gasoline/electric hybrid vehicles but without all the added cost and complexity of gasoline/electric hybrid technology.
The problem, according to Lutz, is that making diesel engines work for the American passenger vehicle market, which is very different from Europe's, will require adding technology. That means adding complexity and cost, just like hybrids. What's worse, along with adding cost and complexity, is that these technologies will also reduce a diesel vehicle's fuel economy, taking away the very reason for turning to diesel in the first place, said Lutz.
The basic problem, according to Lutz, has to do with increasingly tough vehicle emissions standards in the United States. In most of the United States, these standards are already much more stringent than in Europe and they're getting tougher. In some states, those that follow California's emissions standards, these rules are tougher still.
EDIT
http://money.cnn.com/2007/07/13/autos/lutz_on_diesel/index.htm